Lumber spray machine



A. D. CHAPMAN ET AL 3,343,519

LUMBER SPRAY MACHINE 4 Sheets-Sheet 1 INVENTORS A. DALE CHAPMAN ROBERTE. BRANCH ROBERT E. STUTZ BY ATTORNEY H I HF MP HM i ml Sept. 26, 1967Filed June 24, 1963 F WM a? I i wurn Q GWI MQ/ Sept. 26, 1967 CHAPMAN ETAL 3,343,519

LUMBER SPRAY MACHINE Filed June 24, 1965 4 Sheets-Sheet 2 INVENTORS A.DALE CHAPMAN ROBERT E. BRANCH ROBERT E. STUTZ ATTORNEY P 1957 A. D.CHAPMAN ET AL LUMBER SPRAY MACHINE 4 Sheets-Sheet 3 Filed June 24, 1963I'll INVENTORS A DALE CHAPMAN ROBERT E. BRANCH ROBERT E. STUTZ BY W6ATTORNEY P 1967 A. D. CHAPMAN ETALL 3,343,519

LUMBER SPRAY MACHINE Filed June 24, 1963 4 Sheets-Sheet 4 mg'M-- V :31939m INVENTORS A. DALE CHAPMAN I06 I06 ROBERT E. BRANCH ROBERT E. STUTZATTORNEY I i l I I I I 2 4 United States Patent 3,343,519 LUMBER SPRAYMACHINE Alfred Dale Chapman, Atherton, and Robert E. Stutz,

Ialo Alto, (Ialifi, and Robert E. Branch, Memphis,

Tenn, assiguors to Chapman Chemical Company,

Memphis, Tenn, a corporation of Illinois Filed June 24, 1963, Ser. No.289,995 Claims. ((31. 118-614) This invention relates to a lumber spraymachine and more particularly to a machine for spraying lumber forpreservative treatment thereof.

It has long been the practice to treat lumber such as poles, piling,ties, timber and the like in order to extend their useful life. Variousprocesses for treating lumber with a preservative are well known andinclude pressure, dipping, and spraying processes. Prior art sprayingapparatus has as a rule been unsatisfactory due, among other things, tothe lack of control of mixing, feeding and application of the solutionsprayed. The pressure processes are generally slow and expensive and arenot well adapted to large scale use. The practice of dipping lumber hasmany disadvantages including the high cost, the possible over treatmentthrough lack of control of the application and the like.

In order to reduce storage, shipping, and related costs it is a commonpractice to prepare wood preservatives in a concentrated form. Theconcentrated preservative is then diluted in a suitable liquid base suchas water or an organic solvent and the diluted solution applied to thelumber. The lumber spray apparatus of this invention is particularlyuseful with such concentrated wood preservatives and serves to dilutethe concentrate with a base liquid, stores it, and applies it uniformlyto all faces (if desired) of a board or timber.

Depending upon the type of wood preservative employed, either anemulsion or a solution may result from the mixing of the concentratewith the base fluid. Although the apparatus of this invention may beused with either an emulsion or a solution of wood preservative theapparatus is particularly adapted for use in spraying an emulsion.Emulsions are particularly difiicult to apply by spraying to lumberbecause of plugging of the nozzles, and breaking of the emulsion due todirt, sawdust, and other contaminants which get into the emulsion duringoperation of the machine.

An object of this invention is the provision of a machine for sprayinglumber which machine functions to dilute a concentrate to form asolution or emulsion, store the resulting diluted preservative in aproper form and concentration, apply the preservative uniformly to thelumber regardless of species, and to recover, recirculate, and reuse thesurplus preservative to minimize cost, fire hazard and irritation toworkmen.

An object of this invention is the provision of a lumber sprayingmachine which machine is capable of spraying a sensitive wax emulsionwithout breaking the emulsion, that is, without separation of the waxconcentrate and the base solution.

An object of this invention is the provision of a lumber spray machinefor spraying lumber with a wood preservative which machine includes anovel arrangement of strainers and screens to reduce clogging of spraynozzles to a minimum.

An object of this invention is the provision of a wood spraying machinewhich includes strainers, screens, and spray nozzle assembly, all ofwhich are readily and easily removable from the machine and replaceabletherein with a minimum of time and eiiort for cleaning thereof whileremoved from the machine.

An object of this invention is the provision of a storage tank for aspray-type machine for spraying a wood preser- 3,3435 1 9 Patented Sept.26, 1967 vative onto lumber, which tank includes a simple, low costbuilt-in agitator which permits easy and efficient agitation of thepreservative for uniform mixing thereof.

An object of this invention is the provision of a novel hood assemblyunder which spray nozzles and strainers of a lumber spraying machine arelocated which is mounted to permit easy access to said nozzles andstrainers for cleaning and replacement rapidly and efli ciently.

These and other objects and advantages of this invention are obtained bymeans of a spray machine comprising a storage tank divided into aplurality of individual compartments. While the wood preservative isbeing drawn from one of the tank compartments and sprayed upon thelumber, the base liquid and concentrate may be added to the othercompartment and mixed in preparation for use when the first compartmentis empty. An agitator comprising a pivotally mounted agitator vane islocated within each compartment of the tank, which agitator is adaptedfor manual operation. A tunnel is mounted on the tank through whichtunnel the lumber to be treated is passed by means of drive rollsincluded in the tunnel construction. Also included is a novel spraynozzle assembly which is readily removed from the tunnel when the tunnelhood is opened, and which has guide rails formed thereon for properlyguiding the lumber through the tunnel. The bottom of the tunnelcomprises a spray tank into which the excess wood preservative istrapped and returned to the storage tank through quick change screenswhich filter out foreign matter. A manually operated deflector platediverts the over-spray of preservative from the spray tank to either ofthe storage tank compartments depending upon the position thereof. Adrive motor for the rollers in the tunnel and a pump and pump motor arelocated on a platform on the storage tank adjacent the tunnel. Access tothe storage tank compartments is provided through doors adjacent theplatform upon which the above-mentioned motors and pump are located.

In the drawings wherein like reference characters refer to the sameparts in the several views;

FIGURE 1 is a front elevational view of a lumber spray machine embodyingthis invention;

FIGURE 2 is a top plan view of the machine shown in FIGURE 1;

FIGURE 3 is a side view as FIGURE 1;

FIGURE 4 is a side view of the machine as viewed from the right inFIGURE 1;

FIGURE 5 is a cross-sectional View of the machine taken on line 55 ofFIGURE 1;

FIGURE 6 is a perspective view of an interchangeable spray nozzleassembly employed in the machine of this invention;

FIGURE 7 is an enlarged fragmentary sectional view of the hood taken online 77 of FIGURE 3;

FIGURE 8 is an enlarged fragmentary view of the header employed in thespray nozzle assembly, with parts shown broken away for clarity;

FIGURE 9 is an enlarged fragmentary view of a nozzle and nozzle mountingemployed in the spray nozzle assembly; and

FIGURE 10 is an enlarged fragmentary sectional view of the baflleassembly at the bottom of the spray tank.

Referring now to FIGURES 1 to 5 of the drawings, reference numeral 10designates generally a lumber spray machine embodying this invention.The base of the unit comprises a storage and mixing tank 11 mounted uponlegs '12. The tank comprises side walls 13 and 14 and end walls 16 and17 and is divided into two compartments designated 18 and 19 by means ofa partition 21 which extends between the side walls 13 and 14, and fromthe inclined bottom 22 of the tank to the top thereof. Agitaviewed fromthe left in tors comprising vanes 24 with pins 26 extending from theends thereof and pivotally supported in V-shaped blocks 27 secured tothe inner face of the side walls 13 and 14 of the tank are located ineach of the tank compartments. While any suitable tank construction maybe employed the illustrated construction includes a framework of anangle iron comprising members 29 which extend from end to end and sideto side across the top of the tank. Access to the tank compartments 18and 19 is available through doors 34 and 36, pivotally mounted by meansof hinges 37 on a base plate 3 8 extending between two of the members29' 'of the tank frame.

The one door 36 is shown opened in FIGURES 1 and 42 of the drawings anda rod 39 is shown inserted in a tubular bracket 41 fixed to the agitatorvane 24. By manually rocking the rod 39 back and forth the agitator vane24 is actuated to mix the liquid within the tank compartment. The samerod 39 may be calibrated in gallons, for example, along the lengththereof and used as a dip stick to indicate the amount of fluid withinthe tank compartments, such a dip stick measuring device beingparticularly useful in adding the right proportion of wood preservativeconcentrate and base fluid to the tank compartments to obtain the properdilution of the wood preservative concentrate.

At the side of the tank opposite the doors 34 and 36 is located a tunnel42 through which the lumber to be treated is passed. The tunnel 42comprises a spray tank 43 which includes end walls 44- and 46 and sidewalls 47 and 48. The bottom of the spray tank comprises spaced bottomsections 49 and 51 as best seen in FIGURES 3 and of the drawings whichsections are inclined downwardly toward each other to permit drainage ofthe excess Wood preservative therebetween. Three power-driven rollers 52extend between the side walls 47 and 48 of the spray tank and arecarried by bearings 56 attached to the outer surfaces of the side Walls.Shaft seals 57 located between the roller shafts and the apertures inthe side walls through which the shafts extend prevent entrance of thewood preservative onto the bearings. It will be noted that the sidewalls 47 and 48 of the spray tank extend above the level of the top ofthe rollers 52 whereas the end walls 44 and 46 terminate at the upperend thereof a spaced distance below the upper roller surface. V-shapedguards 59 secured to the upper edge of the end walls 44 and 46 preventinadvertent entrance of lumber or foreign articles beween said end wallsand the end rollers 52.

Spray tank 43 is adapted to be covered by a semicylindrical hood 61which rests upon the side walls 47 and 48 of the'spray tank. The lowerlongitudinal edges of the hood are bent inwardly as at 62 (see FIGURE 7)to form a ledge which seats upon the longitudinal upper edge of the sidewalls 47 and 48 of the spray tank and terminate in downwardly dependentportions 63 which extend within the spray tank side walls when the hoodis in position thereon. Generally semicircular rings 64 are secured tothe hood 61 a spaced distance inwardly from each end of the hood andeach such semicircular ring supports a flap 66 provided with a pluralityof vertical slits 67 extending from the bottom thereof to permit theingress and egress of lumber through the tunnel. The flaps may be madeof impregnated plastic fibers or the like which material is not affectedby the wood preservative sprayed within the tunnel. The flaps, whichhelp to keep the sprayed wood treating material within the tunnel,extend downwardly lower than the upper edge of the end walls 44, 46,inside the spray tank in the normal hood closing position. Instead ofutilizing a removable hood it will be understood that the hood could behinged along one edge thereof to the edge of the spray tank forpivotally supporting the same thereon, if desired.

Located within the tunnel 42 is a spray assembly 71 for spraying of thelumber as it passes therethrough. The spray assembly 71, as best seen inFIGURE 6, comprises a pair of spaced ring-like nozzles supportingmembers ,72

interconnected by a pair of lumber guide rails 73 attached within therings at opposite sides thereof. The ends of the lumber guide rails areflared outwardly as at 74 to guide the lumber between the rails.Brackets 76 are secured as by screw fastening devices 77 to thering-like nozzle supporting members 72 adjacent the upper and lowerportions thereof. The brackets 76 are formed with generally verticalextending apertured arms through which apertures degree elbows 78 extendand are fastened thereto by set screws 79. Nozzles 81 are carried by the90 degree elbows 78 and by loosening the set screws 79 the elbows 78with the nozzles 81 thereon may be positioned as desired to obtain thedesired spray pattern and then locked in position by tightening of theset screws. Similar brackets 82, FIGURE 9, are mounted on the guardrails 73 adja: cent the ring-like members 72 for the support of sidenozzles 81. The brackets 82 are formed with generally horizontallyextending apertured arm portions which extend through cut-out portions83 formed in the guard rails 73. 90 degree elbows 78 extend through theapertures in the brackets and are fastened thereto by set screws 79. Thenozzles 81 are carried by the 90 degree elbows and, as with the top andbottom nozzles, the side nozzles 81' may also be positionally adjustedby first loosening set screws 79 and positioning the nozzles by rotationof the 90 degree elbow within the bracket arm and then locking the elbowwith the set screw.

The nozzles are all connected to a header or manifold 84 through hoses86 extending between the 90 degree elbows 78 and the manifold 84. Themanifold 84 is best seen in FIGURES 6 and 8 and may comprise a generallyrectangular shaped tube plugged at opposite ends by end plugs 87. Screwfastening means 88 extending through the ring-like members 72 supportthe manifold between the said ring-like members. The hoses 86 areprovided with suitable coupling members 89 at the opposite ends thereoffor connection to said elbows and manifold. A supply hose 91 isconnected through a coupling 92 to the manifold and is provided with aquick disconnect female coupling member 94 adapted for quick connectionand disconnection with a male coupling member 96 (shown in FIGURES 2 and5) fastened to the spray tank side wall 48 and extending therethrough.The coupling member 96 is connected to a pump for the wood preservativein a manner described hereinbelow. Nozzle guards 97 are secured to theguard rails 73 at the upstream side of the tunnel to deflect the lumbertoward a center position between the guard rail and prevent the samefrom contacting the nozzles and damaging the same.

The spray assembly is supported in the spray tank 43 by means of arms 98extending forwardly and rearwardly from the respective forward andrearward ring-like members 72 which arms are adapted to rest uponbrackets 99 secured to the side walls 47 and 48 0f the spray tank. Thus,it will be apparent that when the hood 61 is removed from the spray tankthe spray assembly is easily and quickly lifted therefrom afterdisconnection of the quick disconnect coupling member 94 from the malecoupling 96. In practice a standby, or auxiliary, spray assembly 71 isprovided whereby the spray nozzle assemblies may be interchanged whenrequired. Thus, if one or more of the nozzles 81 or 81' become pluggedor blocked the entire spray nozzle assembly 71 may be removed and asecond spray nozzle assembly replaced in the machine, all within aboutone minutes time. The down time of the machine due to clogged nozzles isthereby reduced to a minimum.

With the arcuate or generally semicylindrical shaped hood 61 the excessmaterial which is sprayed from the nozzles 81, 81' striking the hoodruns down the inner walls thereof and drops from the side edges therebyavoiding dripping of the material onto the lumber being sprayed. Theexcess material falls within the spray tank 43 and flows down theinclined bottom portions 49 and 51 of the tank. A bafile assembly shownin FIGURE for directing the return flow of preservative from the spraytank to the storage tank is fixed to the bottom of the storage tank andincludes transverse angle members 100 and 101 secured to the lower edgeportions of the tank bottom members 49 and 51 and extending between theside walls 47 and 48 of the tank. Screen supporting brackets 102 arewelded between the angle members 100 and 101 adjacent the side walls 47and 48 of the spray tank and support a pair of screens 103 which extendtherebetween. The screens 103 are separated by a T- shaped screenretainer member 104 which extends between the side walls 47 and 48 ofthe tank and is secured thereto as by welding. The screens are placed inposition in the bottom of the spray tank by first resting an edgethereof on the side ledges or brackets 102 and sliding the screen edgesunderneath the extending arm portions of the T-shaped screen retainer104. Thus, it will be apparent that all the sprayed wood preservative isscreened as it is returned to the storage tanks. The screens are readilyremovable for cleaning and replaceable when the hood and spray assemblyhave been removed from the spray tank.

At the bottom side of the horizontal arm portions 106 of the anglebrackets 101, second angle brackets 107 are secured as by welding, whichbrackets are located at the opposite ends of the angle brackets 101adjacent the side walls 47 and 43 of the spray tank and includedownwardly extending portions between which the flow of material isconfined. Bottom baffle plates 108 which are inclined toward each otherare fixed to the bottom surfaces of the arm portions 106 of the anglebrackets 101 and extend between the downwardly directed arms of theangle brackets 107. The lower transverse edge portions of the inclinedbaffie plates 108 are spaced apart with one edge terminating a spaceddistance from the partition 21 on one side thereof and the other baffieplate terminating a spaced distance from the partition at the other sidethereof within the respective tank compartment 18 and 19. A right anglemember 109 having a plurality of notches 111 formed along the oppositelongitudinal edges thereof is fixed to the upper surfaces of the baffleplates 108 in an inverted V-shape position and bridges the gaptherebetween.

A pivotal deflector plate 112 is located within the baffle assemblybeneath the screens 103, and is mounted upon a rod 113 which extendsbetween the side walls 47 and 48 of the spray tank. The deflector plateis attached to the rod by means of hubs 114 Welded or otherwise suitablysecured to the deflector plate at opposite ends thereof. Set screws orthe like may be used to secure the hub members 114 to the rod wherebypivotal movement of the rod results in a rocking of the deflector member112. The outer, free end of the rod 113 which extends through the sidewall 47 of the spray tank is provided with a handle 116, FIGURE 3, whichis movable between stop members 117 extending from the side wall. Withthe handle 116 pivoted to the left in a counter clockwise direction asviewed in FIGURE 3 of the drawings the baffle plate 112 is tilteddownwardly to the left whereby the excess wood preservative drainingthrough the screens 103 strikes the bafiie plate and flows downwardlytherealong past the bafi le members 100, 101 and 108 and through thenotches 111 formed in the member 109 and into the tank compartment 18.By rotating the lever 116 to the right against the righthand stop theexcess preservative is returned to the other tank compartment 19. Thestop members 117 for the handle 116 limit the pivotal movement of thedeflector plate 112, such that the plate is at all times a spaceddistance above the arms 106 of the baffle element 101 thereby permittingthe flow of fluid past the said pivotal deflector and over the armportion 106 of the angle members 100 and 101. Thus, it will be apparentthat the operator may control the tank compartment into which the excessspray wood preservative is returned by the simple movement of the leverarm 116.

The power units for the drive rollers 52 and for the pump for sprayingthe wood preservative from the nozzles 81 and 81' are located upon aplatform 121 positioned adjacent the tunnel 42, between the tunnel andthe tank doors 34 and 35. A roller drive motor 122 is shown connectedthrough a variable speed transmission 123 and a belt connection 124 tothe shaft 126 for the center roller 52 through pulleys on the said shaftand the motor shaft. The end rollers 52 are driven through beltconnections 127 and 128 extending between pulleys on the shaft 126 ofthe center drive roller 52 and pulleys on the shafts of the forward andrear drive rollers 52. The rate of rotation of the drive rollers iscontrolled by a speed control lever 136 associated with the variablespeed transmission 123. With an infinitely variable speed drivemechanism the lumber may be driven through the tunnel 42 with a speed inthe range between zero and 1,000 feet per minute, for example.Obviously, for a fixed rate of travel of lumber, the rollers could bedriven at a constant speed and the variable speed transmissioneliminated from the connection between the motor 122 and rollers.

Also mounted upon the platform 121 is a pump motor 138 and associatedvariable speed transmission 139. As with the roller drive, the speed ofrotation of the output shaft 141 of the transmission is controlled by aspeed control lever 142 associated with the transmission. A belt 143 andpulley connection between the transmission shaft 141 and the shaft of apump 144 connects the transmission to the pump. If the spray unit to beused for spraying an emulsion the pump 144 is, in accordance with thisinvention, of the constant displacement diaphragm type. By use of such aconstant displacement pump the emulsion is not broken during the pumpingoperation.

Intake pipes 146 and 147 of identical construction, but provide withdifferent reference characters for purposes of description, extend intothe tank compartments and terminate a short space distance from thebottom thereof. The upper ends of the intake pipes 146 and 147 terminatein male members 148 of quick disconnect type connectors. A hose 149 fromthe inlet side of the pump 144 is provided with a female connectormember 151 for cooperation with either of the inlet pipes 146 or 147through the male connector members 143. Thus, the operator may pump fromeither of the tank compartments 18 or 19 by connection of the hose 149to either of the inlet pipes 146 or 147 to the compartments. It will beapparent that a suitable valve arrangement could be employed in place ofthe quick disconnect coupling 148 and 151 in the connection of the pump144 to the storage tanks 18 and 19.

The outlet from the pump 144 is connected through a hose, or tube, tothe inlet side of an in-line strainer 150, the outlet side of whichstrainer is connected to the spray assembly 71 through a hose 152 andthe hose 91. The hose 152 has .a female coupling member 153 at one endthereof which cooperates with the male coupling member 96, extendingthrough the side wall 48 of the spray tank 43 for interconnection of thehoses 91 and 152. A second hose 154 connects the pump by-pass connectionwith the interior of the spray tank through a coupling 156 in the sidewall 48 thereof.

The operation of the lumber spray machine with a concentrated woodpreservative will now be described. First, one of the dual compartmentsof the tank 11 is filled with the desired amount of base fluid withwhich the concentrate is to be mixed. For example, if a wax emulsionconcentration is to be used, the tank com partment would be filled tothe desired level with water. As mentioned above, the rod 39 could becalibrated in terms of gallons to indicate the water depth within thestorage tank when the rod 39 was held upright on the bottom. After theone compartment is filled with the desired amount of water, the waxemulsion concentrate is added in the proper amount for the desireddilution ratio. In a manner described above the rod 39 is then insertedinto the tubular bracket 41 fixed to the agitator vane 24 and the vaneis pumped 15 to 20 strokes to thoroughly mix the base fluid andconcentrate. With the spray assembly and hood in place on the spraytank, the inlet hose 149 connected to the proper inlet pipe in the tankcompartment containing the preservative, the drive motor 122 and pumpmotor 138 are started by turning on switches 161 and 162 located on theside of the platform 121 and electrically connected to the motors and toa suitable source of power not shown. The spray pattern from the nozzles81, 81' may then be checked by lifting the flaps 66 of the tunnel andthe nozzle positions adjusted if necessary to obtain the desiredpattern. Both the rate at which the lumber is passed through the spraytunnel and the pressure at which the preservative is sprayed from thenozzles are controlled by the variable speed transmissions 123 and 139to provide the correct application rate of the wood preservative on thelumber. (Obviously, if fixed drives are used, no adjustment of the ratesis possible.) With the nozzles at the forward end of the tunnel directedrearwardly and the nozzles at the rear of the tunnel directed forwardly,it will be apparent that both faces, edges and ends of the lumber willbe treated with the preservative. If desired, the machine can be readilyadapted to permit application of wood preservative to both edges, endsand one face only by plugging the bottom nozzles and installing a set offelt roll Wipers in a manner well understood by those skilled in thisart.

Also, although the lumber spray machine may be located at any desiredpoint in a lumber processing line, a preferred location is directlybehind the planer, since such a location often involves little or noadditional labor and requires a minimum of floor space. In many cases noadditional floor space is required since the spray unit replaces theso-called hurry-up belt used behind many planers. This location is alsoadvantageous because the lumber is under control at this pointminimizing the chance of a jam or hang-up in the spray tunnel. Theplaning machine operator can be made responsible for the spray machineas all the controls are conveniently lo cated. Where end trimming occursbehind the planer, ends may be sprayed from a small portablehand-operated spray gun after the lumber has been pulled and staked.Lumber may be fed into the tunnel of the machine from the oppositedirection to that illustrated by simply reversing the position of thespray assembly end-for-end in the spray tank, and reversing thedirection of rotation of the drive rollers 52. Thus, it will be apparentthat lumber may be fed through the machine in either direction with aminimum of changes and without having to turn the entire machine around.

While the lumber is being sprayed with a wood preservative from onetank, the operator may be filling the other tank with water and aconcentrated wax emulsion in preparation for use after the first tank isemptied. When the one tank compartment is emptied, the inlet hose 149 istransferred from one inlet pipe in the one compartment to the otherinlet pipe in the full tank compartment with a minimum of down-time. Atall times the proper strength solution or emulsion is being sprayedsince the preparation of the diluted solution is effected in a separatecompartment from which the preservative is being drawn. In operation,the return control handle 116 is positioned toward the tank being pumpedin order that the excess spray may drain back into the tank from whichit came. When switching over from one tank to another, the controlhandle 116 is also turned to deflect the excess spray into the propertank.

The over-spray, as mentioned above, is returned to the storage tankthrough the quick change screens 103 which filter out foreign matter,and the output from the pump 144 is filtered through the strainer 150 intraveling to the nozzle The screening and straining operations reduceclogging of the nozzles to a minimum. As the inline strainer fills withdirt and contaminants, the pressure drop there across increases. Suchincrease in pressure drop may be compensated for by increasing the pumpspeed by means of the control handle 142 in the variable speedtransmission 139. Whenever the readings on pressure gauges designated163 and 164 at the inlet and outlet sides, respectively, of the in-linestrainer indicate a differential of 30 pounds per square inch or more,the in-line strainer 150 should be cleaned or replaced. The pump speedis controlled to provide a pressure of approximately 22 p.s.i. at thegauge 164.

Whenever the lumber spray machine is used with a wood preservative whichdries and hardens and thereby tends to clog the system (a preservativeof the wax emulsion type, for example) the entire system should beflushed and cleaned periodically. For example, at the close of theworking day, or whenever the machine is to be shut down temporarily, theentire system should be flushed and cleaned. This may be done by firstemptying the tank compartments either 'by use in spraying lumber or byopening drain plugs 171 in the bottom thereof. With the plugs 171closed, a quantity of water (say 10 to 15 gallons) may be added to onecompartment and the water circulated for a period of time at anincreased pressure of about 50 p.s.i. The over-spray may then bereturned to the other compartment by means of the return control handle116 and the one tank pumped empty. This procedure may then be repeatedagain by adding another 10 to 15 gallons of water to the empty tank andcirculating the same under high pressures. After about a total of 5minutes of such flushing, the water may be returned to the opposite tankcompartment. When the flushing has been completed the opposite tankcompartment will contain the small amount of wax emulsion left over inthe system from the treating just completed plus the 20 to 30 gallons ofwash water. Water may now be added to this other compartment to thelever required for the next days operation, thereby preparing thecompartment for new wax emulsion concentrate to be added at the start ofthe next shift. Any time the machine is to be shut down for any extendedperiod of time both tank compartments should be drained and flushed.

The invention now having been described in detail in accordance with therequirements of the patent statutes various changes and modificationswill suggest themselves to those skilled in the art and it is intendedthat such changes and modifications shall fall within the spirit andscope of the invention as recited in the following claims.

We claim:

1. A lumber spray machine for spraying lumber with a wood preservative,or like material, comprising a storage tank for material to be sprayed,a spray tunnel comprising a spray tank covered by a hood, a plurality ofspray nozzles in the tunnel, said plurality of spray nozzles beingintergally formed in a nozzble assembly which is remova-bly mounted inthe tunnel, the nozzle assembly comprising a pair of spaced ring-likemembers interconnected by a pair of spaced guide rails, means forpassing lumber through the tunnel, lumber to be sprayed travelingthrough said ring-like members and between said guide rails in passingthrough the tunnel, means for pumping material from the storage tank tothe nozzles for spraying lumber passed through the tunnel, and means forreturning over-spray from the tunnel to the storage tank.

2. The invention as recited in claim 1 wherein the nozzle assemblyincludes a header attached to the spaced ring-like members and extendingtherebetween, means connecting the nozzles to the said header, anddetachable coupling means for connecting the header to the said meansfor pumping material from the storage tank.

3. A lumber spray tunnel within which lumber passing therethrough may besprayed with a wood preservative, or like material, said. spray tunnelcomprising a spray tank, a hood to cover the spray tank and movablebetween open and closed conditions, a spray assembly including aplurality of spray nozzles, means including a readily disconnectablecoupling for connecting the spray assembly to a source :of material tobe sprayed, and means readily removably mounting the spray assembly inthe spray tank, the said spray assembly being readily removable from anreplaceable in the spray tank when the said hood is moved to an openedcondition and said coupling is disconnected, said hood being of agenerally semi-cylindrical shape and having flexible slit flaps at theends thereof through which lumber passes into and out of the tunnel, thesemi-cylindrical hood resulting in over spray striking the hood flowingalong the inner Wall thereof to the edges and thence dripping into thespray tank Without dripping on the lumber passing through the tunnel.

4. A lumber spray tunnel within which lumber passing therethrough may besprayed with a Wood preservative, or like material, said spray tunnelcomprising a spray tank, a hood adapted to cover the spray tank in aclosed hood condition, a spray assembly including a plurality of spraynozzles, means removably mounting the spray assembly in the spray tank,the said spray assembly being removable from and replaceable in thespray tank When said hood is moved to an opened condition, said sprayassembly comprising a pair of ringlike members spaced along thelongitudinal axis of the tunnel, and a pair of guide railsinterconnecting said ringlike members and extending outside of thetunnel beyond the ends thereof, the lumber to be sprayed passing throughsaid ring-like members and between the guide rails.

5. The invention as recited in claim 4 including drive rollers extendingtraversely across the spray tank, the upper surface of the drive rollersbeing at a greater height than the front and rear walls of the spraytank to permit lumber to pass thereover on the said rollers, and meansdriving the said rollers.

References Cited UNITED STATES PATENTS 1,680,106 8/1928 Manning 134-82 X2,651,312 1/1953 McBeth 134-165 X 2,912,988 11/1959 Kochendorffer 134l65X 3,178,745 4/1965 Kleebauer 1577 FOREIGN PATENTS 1,256,013 2/1961France.

CHARLES A. WILLMUTH, Primary Examiner. DANIEL BLUM, Assistant Examiner.

1. A LUMBER SPRAY MACHINE FOR SPRAYING LUMBER WITH A WOOD PRESERVATIVE,OR LIKE MATERIAL, COMPRISING A STORAGE TANK FOR MATERIAL TO BE SPRAYED,A SPRAY TUNNEL COMPRISING A SPRAY TANK COVERED BY A HOOD, A PLURALITY OFSPRAY NOZZLES IN THE TUNNEL, SAID PLURALITY OF SPRAY NOZZLES BEINGINTERGRALLY FORMED IN A NOZZLE ASSEMBLY WHICH IS REMOVABLY MOUNTED INTHE TUNNEL, THE NOZZLE ASSEMBLY COMPRISING A PAIR OF SPACED RING-LIKEMEMBERS INTERCONNECTED BY A PAIR SPACED GUIDE RAILS, MEANS FOR PASSINGLUMBER THROUGHT THE TUNNEL, LUMBER TO BE SPRAYED TRAVELING THROUGH SAIDRING-LIKE MEMBERS AND BETWEEN SAID GUIDE RAILS IN PASSING THROUGH THETUNNEL, MEANS FOR PUMPING MATERIAL FROM THE STORAGE TANK TO THE NOZZLEFOR SPRAYING LUMBER PASSED THROUGH THE TUNNEL, AND MEANS FOR RETURNINGOVER-SPRAY FROM THE TUNNEL TO THE STORAGE TANK.